1. Technical Field
The present invention relates to a motor controller for an air conditioner, and more specifically to a motor controller which sequentially generates a dc terminal signal and simultaneously insulates a dc terminal from a microcomputer.
2. Background Art
Air conditioners are generally arranged in a certain space, such as rooms, living rooms, offices, and stores, to adjust the temperature, moisture, clearness, and air flow to maintain inner environment clean and fresh.
An air conditioner may be commonly classified into an integral type and a stand-alone type. Both types are the same in their functions. In the integral type air conditioner, however, a cooling function has been integrated with a heating function, and the air conditioner is mounted on the wall or window. On the contrary, the stand-alone type air conditioner includes an indoor unit and an outdoor unit that are provided separately from each other. The indoor unit is located indoors for providing heating and cooling. The outdoor unit is located outdoors for heat dissipation and compression. The indoor unit is coupled with the outdoor unit via a refrigerant pipe.
An air conditioner includes a motor used for a compressor or fan, and a motor controller for driving the motor. A typical motor controller controls driving of such a motor by converting AC utility power into DC power and then converting the DC power into prescribed AC utility power with a prescribed voltage using an inverter.
A malfunction of the motor controller may damage circuit elements included in the motor. Therefore, a number of approaches have been considered to prevent such a malfunction.